Given $\displaystyle n=10$ and $\displaystyle p =0.05$

Find $\displaystyle n$ where $\displaystyle P(X< n)=0.8$

I have found

$\displaystyle P(X<1) = P(X=0) = 0.599$

$\displaystyle P(X<2) = P(X=0)+P(X=1) =0.914$

$\displaystyle n \in \mathbb{Z}^+$ ?

So $\displaystyle n= 2$ ? $\displaystyle n$ cannot be a decimal answer.